Surgical sutures often require a surface coating to improve one or more of their performance properties. For example, a multifilament suture typically requires a surface coating to improve the tactile smoothness, and tiedown performance of the suture, so it passes easily and smoothly through tissue during operative procedures
In response to the need for suitable coatings for surgical sutures, numerous patents have disclosed potential coating compositions. U.S. Pat. No. 3,942,532 discloses a polyester coating for multifilament sutures. The preferred polyester coating is polybutilate, which is the condensation product of 1,4-butanediol and adipic acid. U.S. Pat. No. 4,105,034 discloses a multifilament suture coating of a poly(alkylene oxalate), e.g., poly(hexamethylene oxalate). Although the coating compositions disclosed in these patents exhibit excellent handling characteristics and enhance many of the properties of the coated suture, the knot integrity of the coated suture diminishes slightly.
U.S. Pat. No. 3,527,650 discloses a coating composition of polytetrafluoroethylene (PTFE) particles in an acrylic latex. Although PTFE acts as an excellent lubricant to decrease the roughness of multifilament sutures, it has a tendency to flake off during use. Also, this particular coating is a thermoset which requires a curing step for proper application. U.S. Pat. No. 4,043,344 discloses a PLURONICS ethylene oxide/propylene oxide copolymer for nonabsorbable surgical sutures. Unfortunately, these copolymer coatings lose their lubricity during wet tiedown evaluations--most likely due to their tendency to also come off during use.
Silicone has previously been used as a coating for sutures. It is desirable, however, to develop a non-silicone based suture coating which had the same lubrication properties as silicone. Efforts at using existing coatings on sutures previously coated with silicone, or developing a new, non-silicone replacement coating which meets the coating performance properties of silicone, have until now been unsuccessful. Many of these coatings were derived from wax-like based materials.
In view of the deficiencies with the potential candidates for suture coatings, and in view of the desire for non-silicone based coatings, it would be desirable to develop a coating for a suture that can be applied using conventional techniques, and that exhibits all of the superior performance properties which silicone coatings possess (improved tactile smoothness of the coated suture, pliability and knot integrity).
It is therefore an object of the present invention to provide a coated suture which exhibits excellent performance properties, such as tactile smoothness, pliability, and knot tiedown performance.
It is a further object of the present invention to provide a suture having its surface coated with a non-silicone based coating for lubricating the suture surface.
These and other objects and advantages of the invention will become more fully apparent from the description and claims which follow or may be learned by the practice of the invention.